In satellite antenna feed systems, there is frequently a need to convert electromagnetic signals between linear polarization and circular polarization. One approach to converting between these polarization states has been to dispose meander-line polarizers on the optical axes of the antenna feed systems.
Meander-line polarizers experience a number of drawbacks for satellite applications. Meander-line polarizers have little useful bandwidth individually, so numerous meander-line polarizers must be cascaded to be useful over a broad range of frequencies. Individually, meander-line polarizers are inadequate for handling high power loads, and when cascaded, meander-line polarizers experience power loss from the high number of interfaces in the cascade. Furthermore, meander-line polarizer cascades are difficult to fabricate and implement because of the complexity associated with the number of layers, all of which must be precisely oriented with respect to one another and with the optical axes.
Accordingly, there is a need for an affordable polarizer that can convert electromagnetic signals between linear polarization and circular polarization, with greater useful bandwidth, less loss and greater power handling capabilities. The present invention satisfies these needs and provides other advantages as well.